Hydraulic unloading and circulating device



Feb. 9, 1965 L.. L. HUCKABY HYDRAULIC UNLOADING AND CIRCULATING DEVICEFiled June '7, 1965 INVENTOR. LEONARD L. HUCKABY BY 5 TTRNEYS FIGA'apparatus. l i t l 3,168,873 j t HYDRAULC UNLUADING ANB l CMCULATINGDEJllCE s Leonard L. Huckahy, Rte. 2, Box 11S, f Santa Paula, Calif.

Filed `lune 7, i963, Ser. No. 286,402 6 Claims. (Cl. 10S- 221) Thisinvention relates generally to` devices for use in Wells and moreparticularly, to an improved hydrauhc unloading and circulating deviceadapted to be inserted m `within the threaded joint of a well toolsupported on the end of a pipe stringfor passing fluid from the exteriorof the tool to the interior thereof in response to a pulling force bythe pipe string.

The preferred embodiment of the device of this invention is best adaptedfor use when it is desired to pull a pump Vor remove the same from anoil well .and for purposes ofthe present` specification, the tool willbe describedin conjunction with such an operation.

i In order to pump oil from a Well in which casing has :1

been set, the casing is perforated by a suitable gun at those levels inwhich oil has been indicated `to exist. After the casing has beenperforated, a pumping tube is lowered on the end of the conventionaldrill pipe string tojthis particular level and within the pumping tubeitself there is then lowered a pumping apparatus. The lower interior ofthe pumping tube terminates in an annular seat adapted to receive insealing relationship the lower end of the pumping apparatus. The.pumpingapvparatusitself is operated by sucker rods which pass up throughthe pumping tube and pipe string and are recip rocated to operateaplunger `within thepumping apparatus. Oil may thus be pumpedthrough theperforations in the casing and up past the lower annular seat of thepumping tube, throughthe pumping apparatusLand thence upwardly throughthe surface of the well.

After pumping has been completed or if it is desired to change the pumpor repair it, it is necessary to unseat the lower end of the pumpingapparatus from the annular seat defined by the pumping tube. i pumpingapparatus as Well `as theitube itself `is filled with oil throughout aconsiderable length, Whereasthe surrounding uid in the casing exteriorof the pumping tube may be a relatively low 1evel,1thereexists a verylarge pressure 'differential rendering it extremely dilicult` to unseatthe` pump from the` annular seat of the pumping tube. In fact, thesucker rods themselves `through which the pulling force is `applied tothe4 pump maytvery well break before suicient force is applied to unseatthe pump.

within the pipe string and surrounding the pumping apparatus within thepumping tube could `be passed in a reverse Since, however, the l Theforegoing condition may be overcomeif `the liuid t fluidcould be passedin this manner, thelargehydrot.

static head created within the pumping apparatus and pipe stringcouldlbe dumped into the surrounding area of the pumping tube and thusequalize with that outside pressure so that removal of the pumpingapparatus from the annular seat could be very readily achieved. i

It would be desirable in a tool of the foregoing type that the hydraulic`unloading `of the fluid within the pipe string to the exterior of the`tool would only operate in the event `a force greater than that whichmight damage the sucker rodsiwould In other instances of pumpingoperations, the pump tool itself may become stuck in the bore holepandin snch event, it would be desirable to remove at least a portionbrought in to remove the stuck portion,

be required to unseat thepurnping t `of the tool so that suitablefishing equipment c ouldbe n..

incurred.

3,168,873 PatentedfFeb.. 9, 1965 -the lower end-so that unseatingoftheqpump is greatly facilitated. Y

More particularly, it is an object to provide a hydraulic unloading andcirculating device adapted to be inserted at a threaded joint of a welltool without modifying the tool and which includes meansenablingmseparationof two parts making up the device itself to the endthat should a `portion of the tool become stuck, it is a simple matter`to remove the remaining portion leaving an end readily adapted to`cooperate with fishing, equipment.

Stillother objects of this invention` are to provide a hydraulicunloader and circulating deviceadapted to be inserted in the threadedjoint ofa` well tool, which will not disturb normal operation of thetool and yet enables `equalization of the-fluid pressure from about theexterior of the tool with the pressure of uid exerted on the in-.teriorV portion thereof.

i Another object is to provide a` device meeting the foregoing objectswhich isA rugged in construction and reliable in operation.

Brieypthese andmany other objects and advantages of `this invention areattained by providing a sleevecooperating with an inner cylinderpartially telescoped Within 'the sleeve. The inner cylindertitselfincludes aY straight through fluid passage having a lateral portwhich,`whe11 the inner cylinder is in a first telescoped-positiomis`encompassed bythe sleeve so that no uid can pass through thewlateralport. However, when`- the inner cylinder is telescopedI outwardly to asecond position, the lateral port is exposed so that` there is provideda passage for fluid fromthe exterior ofthe device to theinteriorstraight 44throu gh lpassage. t

The lower end of the sleeve terminates in threads `adaptedto belthreadedto thetlower threads of a threaded `joint in theoil well toolwith which the device is to be used. The upper end of' `the innercylinder,- injturn, is threaded to aunique coupling in turn includingthreads for cooperationwithvthe upper threads of the threaded joint ofthe tool. Thecoupling itself-includes left hand threads cooperatingwithfleft handthreads on the upper `end of the inner cylinder such thatthe device may be separated by rotation in` a fright hand direction `ofthe pipe string without loosening any of the other joints. By this`arrangementLshould the lower endof the tool intquestion become stuck,jitis a simple matter to remove the remaining portionof the tube byseparating the coupling from the upper end of.` the inner`` cylinder. jSuitable fishing equipment may thenfbe` lowered. j

Normally, then inner cylinder is held with respect to the -sleeve byshearnpins so that a force in excess of a predetermined force isrequired to shean the pins and thustelescope outwardly the inner`cylinder to` expose the port. Accordingly, hydraulic unloading-of tiuidwithin a pipe `string to the exterior of the tool bypassing the iluiddown .inwardly to the ltool is onlyeifectedin response to an upwardlypulling on the `drill pipestring. `lll/'hen `the device islused with apumping apparatus, this predetermined force is less than that whichwouldf damage lthe sucker rods so that hydraulic unloading of fluidwithin the pipe istring to` facilitate unseatingof the pump unit will beeffected before any damage `to the pump sucker rods is A betterunderstanding of the invention will be had by now referring to thepreferred embodiment thereof as illustratedin theV accompanyingdrawings,in which:

FIGURE l is a cross-section of a pumping unit posi- 3 tioned in an oilwell bore hole for pumping oil therefrom;

FIGURE 2 is an enlarged elevational view partly brokenjaway illustratingthe hydraulic unloading and circulating device of this inventionadapted'to be inserted within a threaded joint of the tool shown inFIGURE l;

FIGURE 3'is -a viewsimilar to FIGURE 2, but illustrating thecomponents-of the device in a position to eiect a `hydraulic unloadingoperation; and,

FIGURE 4tis a perspective view of a clutching arrangement employed withthe device illustrated in "FIG- 'URES 2 and 3.

Referring first to FIGURE 1, there is shown an oil well bore hole withinwhich casing 11 has been positioned. As shown in the lower left handportion of FIG- URE 1, the casing 11 has been perforated as at 12 toadmit oil from the surrounding formations to the interior of the casing.This oil is designated by the numeral 13. When pumping is required toremove the oil, the pressure of oil passing through the perforations 12is not great and therefore the oil level within the casing 11 may berelatively low, such as indicated by the level line 13. l

vTo pump the oil 13 to the surface, there is first lowered a pumpingtube 14 terminating at its lower inner end in an Vannularsea-t 15. This-seat 15 in turn is arranged to cooperate with a pumping apparatusincluding a pump barrel 16. YThe lower end ofthe pump barrel 16 heats inseating relationship on the seat 15 and includes a threaded joint asindicated at 17 generally relatively close to the A i seated end..Within lthe pump barrel 16, thereis included V,al flower annular seat1'8and ball valve 19. A plunger f20in turn is positioned above the ball 19and itself includes-at its Vupper end an annular seat 21 Vand a secondball'` valve V22. The upper end of the plunger 20 is cou- 'pled bya'spider structure 23 `to sucker rods 24 so that the plunger L20 may bemoved in an up and-down direction.

. VSmall ports'25 Vare-provided at the'upper Vend of the pump ibarrel 16yso'that oil pumped -up by the movement of the 'Iplun'ger20 will pass`upwardly to the surface of the bore hole through'the pumping tube 14.

4 Thus, in the operation of thepump described in FIG- 4URE 1, 7upwardmovement of the plunger 20 byy pulling on the sucker rods 24 willv,result in the ball 19v unsea-ting from t-he seat 18 and oil passingupwardly within the pumping barrel16 above the ball 19,. Subsequent'downward movement of the plunger 20 will thenkclose the ball 19 on `theseate1^8 andthus the oil entrapped will be forced past the hall22fwhichgwill be unseated from the seat 21. T he next upwardmovement ofthe plunger 20 will then "'-lift ythis oil''o'ut 'through theopeningsr25 and up through the pumping tube 14'to the surface of thewell.

When -it is desired to remove the pump barrel 16, it is normal practiceto simply pull on sucker rods 24 until the "lower'erid of the barrel isunseated from theannular seat "15 ofthe 'pumping tube 14. The entirepumping apparatus may then be raised `to thej surface of the bore hole.

-However, sincethe pressure exerted on the pump barrel 16 bythehydrostatic head ofoil within the pumping tube '14 is considerablygreater than the pressure of the oil 13 vwithin the casing 11, the pumpbarrel 16 is held by hydroqstatic pressure on the-seat 15. In otherwords, the pressure exerted up through the lower end of the pumping tube14 past the annular seat 15 is very -low since the height of the oilindicated bythe level 'line 13 is relatively low, whereas the pressure`on the upper side of the extending to the surface ofIflthelaforementioned hydrostatic head of oil within `thepumping tube 14could be relieved by passing the o il within the tube to the exterior ofthe pumping apparatus,

' unloading is achieved by inserting a device in the threaded 'position'as shown.

41. joint 17 of the pump barrel 16. This device is illustrated inFIGURES Y2 and 3, and as shown, includes a sleeve 26 terminating at itslower ends in threads 27 adapted to be threadedly connected to the lowerthreads of the joint 17 of the pump barrel 16 of FIGURE 1. Cooperatingwith the sleeve 26 is an inner cylinder 28 partially telescoped thereinas shown and including an internal straight through passage 28'.Cylinder 28 terminates at its upper end in a coupling 29, the lower endof this )coupling 29 having left hand threads 30 cooperating with leftVhand threads on the upper end of the inner cylinder 28. The

Vlaterally through the sleeve and partially into the eX- terior sidewalls of the cylinder. Further, there are provided Q-rings suchasindicated at 34 to seal of alateral port 35V included in the straightVthrough central passage 2S ofthe inner cylinder 28. Thus, when thesleeve 26 and-cylindenZS are in their telescoped positions illustratedin FIGURE 2, the port 35 is encompassed by the sleeve 26 and thus isblocked from passing any fluid.

The lower end of the inner cylinder 28 terminates in an enlarged flange36 includingla transverse channel 37. This structure as best shown inFIGURE 4, cooperates with a loWer fitting 38 including a transverseprojecting portion "39 adapted to be received in the channel 37 :whenthe inner cylinder 2S is telescoped to its downward position,

as'illus'trated in FIGURE 2. This clutch arrangement prel vents relativerotation between the Yinnercylinder Z8 and sleeve 26 when the innercylinder is in its Iirst telescope The interior 40 ofthe sleevereceiving .thelower end of the' cylinder is of increased diameter todefine an annular shoulder 41. This shoulder serves as a stop againstVthe flange 36 to prevent separation of the ,cylinderandusleeve Inoperation,=ifthe device of FIGURE '2 isthreaded within the threadedjoint 17, normal pumping operations can take place. However, when it isdesired -to remove the pumping unit as by unseating the same from theannular seat 15, an upward force is exerted on the sucker Ifjtheforce'required to remove the pump is such lthat it Vmay damage thesucker rods, the shear pins 32 and 33 will shear prior to this time topermit outward telescoping movement of the inner cylinder 28 withrespect to -the sleeve 26. The various components will-then assume thepositions as illustrated in FIGURE 3, wherein it will be no-ted that theport 35 is exposed above the Y sleeve 26.

rpump unit is extremely high because of the tremendous Y Y `hydrostatichead of the oil lthe bore hole.

When the portions/0f the vdevice are in the positions illustrated inFIGURE 3', it will be immediately evident that g fluid 'may now passthrough the port 35 and down through j the'centr'al passage and outtheend past the annular seat 15 of the pumpingy tube illustrated inFIGURE l. The

fluid within'the pump-ing tube 14 is passedto the exterior of thepumping tube and thus no longer exerts a large hydrostatic pressureonthe pump barrel 16. It is thus a Vsimple matter to unseat the pumpbarrel 16 and ralse the e Y unit to the surface ofthe bore hole. e

If,4for some reason, the shear pins 32 and 33 should not shear oroutward telescoping movement is prevented, or

vif the lowerend ofthe pump barrel V16'becomes stuck and it is desiredto still remove the pump unit and eiieet a hydraulic unloading, thekcoupling `29 illustrated in FIG- VURES Zand 3 may be used.` Thus, theinner cylinder 2S will be telescoped inwardly until the clutchengages,thus preventing 4relative rotation between the sleeve 26 and innercylinder 28. If now thel upper end of thepump barrel 16 is caused torotate in a normal clockwise direction, "the lent hand threads 30described in FIGURE-2 will Vrepass fluid downwardly past the seat andthus effect the desired hydraulic unloading. The upper portion of thepumping unit may then be removed Itogether with the coupling 29 and,subsequently, a suitable iishing tool lowered to engage the innercylinder 28 and thence eiiect removal of the remaining portion of thetool.

From the foregoing description, it will be evident that a. greatlyimproved hydraulic unloading and circula-ting device hasrbeen providedwhich will greatly facilitate the removal of pumping apparatus from awell bore by equalizing the hydrostatic pressures tending to hold thepumping unit on the annular seat 15 of the pumping tube. Further, itwill be evident that in the event the tool should become stuck, the factthat the device illustrated in FIG- URES 2 and 3 may be separated as aconsequence-of the use of the coupling 29 with left hand threads enablesremoval of at least a portion of the tool. Fishing of the remainingportion is then greatly facilitated as a consequence of the exposed endof the inner cylinder being available for cooperation with the fishingtools. j

While the invention has been described in conjunction with a particularuse in pumping operations, it should be understood that the device Williind use in other applications without departing from the scope andspirit of the invention. The hydraulic unloading and circulating toolshould therefore not be thought of las limited to the exact embodimentset forth merely for illustrative purposes.

What is claimed is:

1. A hydraulic unloading and circulating device for insertion in athreaded joint in a well tool to equalize fluid pressure between theinterior and exterior of said tool in response to a pulling force onsaid tool, comprising, in combination: `a sleeve threaded to the lowerthreads of said joint; an inner cylinder partiallyjtelescoped withinsaid sleeve, the upper end of said cylinder'being coupled to the upperthreads of said joint, said inner cylinder having a straight throughcentral passage including a lateral port encompassed by said sleeve whensaid inner cylinder is telescoped Within said sleeve to a first givenposition and exposed above said sleeve when said inner cylinder ispulled outwardly from said sleeveto a second position; and, a couplingfor coupling the upper end of said cylinder to the upper threads of saidjoint, said coupling having left hand threads on its lower end, saidcylinder having left hand threads on its upper end to receive saidcoupling, the upper end of said coupling having right hand threads toreceive saidyupper threads of said joint whereby the upper end of saidstraight through passage in said 6 adapted to be inserted in `arthreadedjoint of a well tool connected to sucker rods and supported on the endof a pipe string through which said sucker rods extend for passing uidfrom the exterior of said tool to the interior thereof in response to apulling force by said sucker rods on said tool exceeding a predeterminedvalue, said device comprising, in combination: an outer sleeve havinglower threads for threaded connection to the lower threads of saidjoint; an inner cylinder having a lower end portion telescopicallyreceived in said sleeve, the upper end of said inner cylinderterminating in left hand threads; a coupling having left hand threadsfor connection to said upper end of said inner cylinder and right handthreads for threaded connection to the upper threads of said joint; saidinner cylinder having a straight through iiuid passage including alateral port encompassed by said sleeve when said cylinder is in a firsttelescoped position in said sleeve; and holding means for holding saidcylinder and sleeve in said first telescoped position and responsive toa pulling force greater than said predetermined value to release saidcylinder and permit outward telescoping movement thereof from saidsleeve to expose said port above said sleeve whereby uid may pass intosaid port and to the interior of said tool.

4. A device according to claim 3, in which said holding means compriseslateral shear pins extending through said outer sleeve to projectpartially into the outer surface of said inner cylinder.

cylinder may be exposed by'unthreading of said coupling Y 5. A deviceaccording to claim 4, in which right hand rotation of said sucker rodsand the upper end of tool whenV the portion of said tool below saidjoint is held against rotation unthreads said coupling from the upperend of said inner cylinder to expose the upper end opening of saidstraight through-passage whereby iiuid may pass from the exterior ofsaid tool through said passage to the interior thereof.

6. A device according to claim 5, in which said sleeve includes anincreased diameter internal portion defining an annular shoulder, saidlower end of said inner cylinder being received in said increaseddiameter internal portion and including an annular flange having atransverse channel therein; and the lower end of said increased diameterportion including an upwardly projecting transverse Vportion adapted to-be received in said channel when said inner cylinder is in said iirstposition to hold said inner cylinder and sleeve against rotationrelative to each other when said inner cylinder is in said firstposition, said annular shoulder being adapted to engage the upper sideof said annular flange when said inner cylinder is telescoped to itssecond position to prevent complete disengagement of said inner cylinderfrom said sleeve.

References Cited by the Examiner UNITED STATES PATENTS 1,601,676 9/26Burright 10S-221 2,572,388 10/51 'Redpath 103--221 X 2,752,861 7/56 Hill103-221 2,854,929 10/ 58 McGowen et al 10S-221 LAURENCE V. EFNER,Primary Examiner.-

ROBERT M. WALKER, Examiner.

1. A HYDRAULIC UNLOADING AND CIRCULATING DEVICE FOR INSERTION IN ATHREADED JOINT IN A WELL TOOL TO EQUALIZE FLUID PRESSURE BETWEEN THEINTERIOR AND EXTERIOR OF SAID TOOL IN RESPONSE TO A PULLING FORCE ONSAID TOOL, COMPRISING, IN COMBINATION: A SLEEVE THREADED ON THE LOWERTHREADS OF SAID POINT; AN INNER CYLINDER PARTIALLY TELESCOPED WITHINSAID SLEEVE, THE UPPER END OF SAID CYLINDER BEING COUPLED TO THE UPPERTHREADS OF SAID JOINT, SAID INNER CYLINDER HAVING A STRAIGHT THROUGHCENTRAL PASSAGE INCLUDING A LATERAL PORT ENCOMPASSED BY SAID SLEEVE WHENSAID INNER CYLINDER IS TELESCOPED WITHIN SAID SLEEVE TO A FIRST GIVENPOSITION AND EXPOSED ABOVE SAID SLEEVE WHEN SAID INNER CYLINDER ISPULLED OUTWARDLY FROM SAID SLEEVE TO A SECOND POSITION; AND, A COUPLINGFOR COUPLING THE UPPER END OF SAID CYLINDER TO THE UPPER THREADS OF SAIDJOINT, SAID COUPLING HAVING LEFT HAND THREADS ON ITS LOWER END, SAIDCYLINDER HAVING LEFT HAND THREADS ON ITS UPPER TO RECEIVE SAID COUPLING,THE UPPER END OF SAID COUPLING HAVING RIGHT HAND THREADS TO RECEIVE SAIDUPPER THREADS OF SAID JOINT WHEREBY